Are these two the same species?

[pancakesfordinner]

I caught these two a few weeks apart in my neighborhood. I thought they were the same species: Phileurus truncatus, the triceratops beetle. I thought the one on the right was a male, and the one on the left a female because she has tiny bumps on her head instead of horns. But it seems like in triceratops beetle, both the males and females have identical horns. 

So, is the one on the left actually Hemiphileurus illatus, a species of rhinoceros beetle? And am I still right about the sexes or could the one on the right be female triceratops beetle? Both are apparently found in my region, Phoenix AZ. Hard to believe that two beetles looking so similar wouldn't be in the same genus. 

[Garin]

Yes, both are H illatus. Male and female as you noted. Cool little beetles and fun to keep. You can feed them fresh dead insects. P truncatus is much larger and both the males and females have horns. My sister lives in Phoenix and for some odd reason, she finds a few in her house each summer.

[pancakesfordinner]

Thanks for the response. I'm glad they're the same species. 

I grew up in Phoenix but had never seen them before I moved to a new part of town a couple months ago. I'd be delighted to have a few sneak into my house in summertime